1. Field of the Invention
The present invention discloses a carrier for inserting and removing a core breaker through the bore of drill pipe. A portion of the carrier includes a locking mandrel to anchor the carrier at a preselected location within a drill bit.
2. Description of the Prior Art
U.S. Pat. No. 3,208,531 to J. W. Tamplen discloses a locking mandrel and landing nipple similar to those used in the present invention. The locking mandrel of U.S. Pat. No. 3,208,531 is installed and removed by conventional wireline techniques. Core breakers attached to locking mandrels as shown in U.S. Pat. No. 3,208,531 have been installed in and removed from drill bits by separate trips with wireline tools. The present invention eliminates the first wireline trip because the carrier of the present invention can be moved through the bore of drill pipe and anchored at a preselected location in the drill bit by fluid pressure.
U.S. Pat. No. 3,980,134 to Amareswar Amancharla discloses the use of frangible discs made from brittle glass. The frangible disc used in the present invention could be made from any material, glass, metal, or plastic, that has the desired rupture characteristics.